Self-closing door hinges

ABSTRACT

The hinge comprises a flange attachable to a door jamb and a strap attachable to a door. A cam is fixed to the flange and a follower for said cam has a polygonal rod fixed thereto and protruding therefrom.The rod is insertable into a complementary through hole in the strap from either end of the hole so that the strap can be reversed 180* with respect to the flange. The cam is symmetrical about a transverse diametric plane passing through the axis of the cam. The follower matches the cam. The strap can thus be attached to either a right hand or left hand door. Upon turning the door from closed to open position, the door rises due to coaction of cam and follower, and the door is self closing by gravity.

United States Patent 1 Berkowitz 51 July 31, 1973 SELF-CLOSING DOORHINGES [75] inventor: Irving L. Berkowitz, Binghamton,

N.Y. [73] Assignee: Kason Hardware Corporation,

Binghamton, NY.

[22] Filed: Aug. 18, 1971 [21] Appl. No; 172,737

[52] US. Cl. 16/153, 16/129 [51] Int. Cl E051 1/06 [58] Field of Search16/153, 152, 154, 16/170 [56] References Cited 7 UNITED STATESPATEN-TS3,107,758 10/1963 Benham .7 16/153 3,134,134 5/1964 McCubbin 16/153475,145 5/1892 Oberbeck 16/149 2,817,871 12/1957 Ferry 16/169 2,847,2388/1958 Bolling, Jr 16/169 FOREIGN PATENTS 0R APPLICATIONS 660,612 2/1964Italy 16/170 Primary Examiner-James T. McCall Assistant Examiner-DorisL. Troutman Attorney-J. B. Felshin [57] ABSTRACT The hinge comprises aflange attachable to a door jamb and a strap attachable to a door. A camis fixed to the flange and a follower for said cam has a polygonal rodfixed thereto and protruding therefrom.The rod is insertable into acomplementary through hole in the strap from either end of the hole sothat the strap can be reversed 180 with respect to the flange. The camis symmetrical about a transverse diametric plane passing through theaxis of the cam. The follower matches the cam. The strap can thus beattached to either a-right hand or left hand door. Upon turning the doorfrom closed to open position, the door rises due to coaction of cam andfollower, and the door is self closing by gravity. 1

f 23 Claims, 16 Drawing Figures Pmemwwm 3.748.688

' sum 1 or 4 yam PATENTED JUL 31 3. 748 6B8 sum 2 nr 4 lil wrPAIENIEuJum ms saw u (If 4 SELF-CLOSING DOOR IIINGES This inventionrelates to door hinge hard-ware.

An object of this invention is to provide highly improved door hingehardware of the character described which is reversible for use withright hand or left hand doors and is self-closing for either right orleft hand doors.

Another object of this invention is to provide door hinge hardware ofthe character described so constructed as to ensure that the door isshut tight in closed position of the door.

Still another object of this invention is to provide door hinge hardwareof the character described comprising a flange attachable to a door jamband carrying a cam formed with a bore, and a strap having a through holeof non-circular cross-section, and a follower rotatably and slidablyreceived in said bore and having a cam surface matching the cam surfaceof the cam, and a rod non-rotatably and slidably insertable into saidthrough opening from either end, whereby said strap is reversible 180 inits own plane for use with left hand or right hand doors.

Yet another object of this invention is to provide selfclosing doorhinge hardware in which the cam surfaces on said cam and on saidfollower are similar and symmetrical about a plane passing through theaxis of said cam and follower, and said cam surfaces being such thatsaid door will rise upon opening the door and will self-close the dropdown by gravity when the door is tapped from open position towardclosing position, and will remain in fully opened position when the dooris fully opened, and will remain in closed position when the doorcloses.

A further object of this invention is to provide door hinge hardware ofthe character described provided with a cap to close either side of thethrough hole in the strap when the non-circular rod is inserted into theopposite end of said through hole.

A still further object of this invention is to provide door hingehardware of the character described which permits the straps to be madein various lengths and either of the offset or flush types.

Yet a further object of this invention is to provide improved door hingehardware of the surface type or edgemount type.

Still a further object of this invention is to provide edge-mount doorhinge hardware of the character described, in which the strap isattached to an edge of the door, and is provided with means to permitadjustment of the position of the door relative to the door jamb tocompensate for wear in the door gaskets.

Yet a further object of this invention is to provide in edgemount doorhinge hardware of the character described, a strap having an opening topermit insertion of a screw driver to turn the screws for attaching thestrap to the door edge in adjusted position, and a removable plug orplate to close said opening.

One other object of this invention is to provide a strong, rugged anddurable door hinge construction of the character described which shallbe relatively inexpensive to manufacture, easy to set up and adjust,

which shall be smooth and positive in action, which shall be easy tomanipulate, and which shall yet be The invention accordingly consists inthe features of construction, combinations of elements, and arrangementof parts which will be exemplified in the construction hereinafterdescribed, and of which the scope of the invention will be indicated inthe following claims.

In the accompanying drawing, in which are shown various illustrativeembodiments of this invention,

FIG. 1 is a perspective view of a surface mount, offset type door hingeconstruction on a left hand opening door, in closed position, andembodying the invention;

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a partial view like FIG. 2 and showing the position of thestrap in open door position;

FIG. 4 is a cross-sectional view taken on line 4-4 of FIG. 2;

FIG. 5 is a front elevational view of the door hinge of FIG. I in aright hand opening door condition;

FIG. 6 is an exploded, perspective view of the parts of the hinge ofFIG. 1;

FIG. 7 is an exploded view of the cam and follower of the hingeconstruction of FIG. I with part of the cam rplss aw y d in r s-S e FIG.8 is a perspective view of a surface mount, flush type hinge embodyingthe invention;

FIG. 9 is a perspective view similar to FIG. 1 but showing a shorterstrap arm;

FIG. 10 is a perspective view similar to FIG. 8 but showing a shorterstrap arm;

FIG. 1] is a perspective view of an edge mount hinge embodying theinvention;

FIG. 12 is a cross-sectional view taken on line l2l2 of FIG. 11;

FIG. 13 is a top view of the hinge of FIG. 11 showing a door jamb anddoor to which the flange and strap are attached, respectively, incross-section;

FIG. 14 is a cross-sectional view taken on line 14-14 of FIG. 12;

FIG. 15 is across-sectional view taken on line l515 of FIG. 12; and

FIG. 16 is a cross-sectional view taken on line 16-16 of FIG. 12.

Referring now in detail to the drawing and particularly to FIGS. 1-7,thereof, numeral 10 designates hinge hardware embodying the inventionand comprises a flange 11 attached to a door jamb and a strap 13attached to a door and cooperating with said flange. This hinge is asurface mount hinge and the strap is an offset type strap.

The flange 11, comprises a metal part 16 having a flat back plateportion 17 from which there extends forwardly, an integral socket part18 formed with an upwardly opening socket 19. Plate 17 many extend aboveand also below, and to the sides of socket part 18. Said socket 19comprises an upper cylindrical bore 19a from which there extends,downwardly a part cylindrical portion 19b, forming an upper shelf 19c, abottom surface 19d and a vertical surface 19c parallel to back wall 17and closer somewhat to rear of bore 19a than to the front of said bore.Thus the angular extent of part cylindrical surface 1% is greater thanSurface 19e may have a plurality of vertical spaced ridges'l9f, ifdesired. The bottom wall 20 of socket portion 18 may have a hole 21 atthe axis of bore 19a for the purpose hereinafter explained. The back ofplate 17 and socket portion 18 may be formed with cavities 22 to reduceweight. Plate 17 may have screw holes 170 to attach the flange to a doorjamb by screw 17b.

Fitted into socket l9 and fixed therein, is a cam 23 which may be madeof rigid nylon or the like hard plastic having a low coefficient offriction. Cam 23 has an upper cylindrical part 24 received in bore 19aand a lower part-cylindrical part 25 received in the lower part 1% ofthe socket 19. Part 25 of the cam 23 has a vertical surface 26contacting surface 19c of the socket 19, a bottom wall 27 resting onwall 20, and a horizontal wall 28 resting on shoulder 19c. The cam 23 ishollow having an upwardly opening axial bore 29. The lower end of bore29 is formed with a cam surface 30 which is symmetrical about a verticalplane through the axis of the cam and perpendicular to back wall 17. Camsurface 30 has a bottom dwell 31 furthermost forwardly of the back wall17, a pair of upwardly and rearwardly sloping cam surfaces 32 extendingfrom said dwell portion 31, and a top dwell portion 33 closest to theback wall 17. Vertical planes at all radial angles, through the axis ofthe cam, cut the cam surface 30 along horizontal lines. The cam surface30 is above the bottom surface of walls 27,28 and above surface 26 ofthe cam. Said cam may be grooved at its surface 26 to receive the ridgesl9fof the surface 19e of the socket part 18. The upper end of cam 23 isflush with the upper end of socket part 18. Said cam 23 may be forcefitted into socket 19 or fixed therein in any suitable manner.

The bottom wall of cam 23 has a central or axial opening 270 registeringwith opening 21 but smaller than said opening, to permit said cam to beknocked out of socket 19.

The strap 13 comprises an arm or strap portion 40 having an innersurface 41 contacting the outside or front surface of the door 14, andis attached to the door by means of screws passing through screw holes42 in said strap portion. At one end of said strap portion 40 is anintegral tangent annular hub portion 45 countersunk as at 46, atopposite ends to receive a cap 47 at either one end or the other. Saidannular portion 45 is formed with an axial through opening 48 ofnoncircular shape, here shown for purpose of illustration, as being oftransverse hexagonal shape. Slidably inserted into hole 48 (from eitherend) is a rod 50 protruding downwardly therefrom when its upper end isflush with the upper countersunk 46. Said rod is here shown as alsobeing of hexagonal cross-sectional shape to slidably fit in opening 48.Near the upper end of rod 50 is an annular groove 51 to receive anO-ring 52 to keep the rod from accidentally sliding out of the hole 48.

The lower end of rod 50 is force fitted into a hexagonal socket or blindopening 54 of a cam follower 55. Said follower is also made of hardnylon or other rigid plastic material of low coefficient of friction;Said follower has an outer cylindrical surface 56 and a bottom camsurface 57 which matches the cam surface 30 of the cam 23.

Said socket or opening 54 terminates above said cam surface 57. Thebottom wall of follower 55 is formed with an axial opening 60 to permitrod 50 to be knocked out of the follower.

FIG. 1 shows an offset type strap in which strap portion or arm 40 isforwardly offset with respect to the axis of annular portion 45. Thestrap is shown in FIG. I mounted for a left hand opening door.

The inner surface 41 of strap portion 40 slopes rearwardly and to theright a few degrees so that the door closes on the door jamb slightlybefore the follower cam surface 57 is at the very bottom of the camsurface 30 of the cam 23 to thereby insure full closure of the door.

. When inserting the rod 50in hole or through opening 48, care should betaken to make sure that the low part of cam surface 57 will registerwith the low part of cam 30 when the strap 40 is in fully door closingposition.

The cam surface 57 is symmetrical about a vertical plane perpendicularto back wall 17 if the rod 50 is inserted in hole 48 at the correctangular position relative to said hole.

The door will dwell in its closed, lower position. As the door isopened, the door will rise due to interaction of cam surfaces 30, 57. Ofcourse two or more hinges are used for each door but since all thehinges are the same, only one is shown and described.

As the door is opened by moving the door 180 to the left, coaction ofcam surfaces 30, 57 will cause the door to be raised until the door isfully open, and the swell at the top of the cam surface 30 and at thebottom of cam surface 57 will allow'the door to remain in open position.However, when the door is tapped toward closing position, gravity andthe cam surfaces will allow the door to self close and drop at the sametime.

To use the strap 13 for a right hand door, said strap islifted up offthe flange, and the follower is pulled down to pull the rod 50 out ofhole 48. The strap 13 is then rotated l80 in its own plane so that strapportion or arm 40 extends to the left as shown in FIG. 5 instead of tothe right as shown in FIG. 1. The cap 47 is taken off one end of theannular portion 45 and mounted on the other end thereof. The rod 50 isthen inserted in the opposite end of hole 48, from the bottom upwardlyand the follower slid down into the cam 23. Again care must be taken toensure that rod 50 is inserted at such radial angle that cam surface 57will contact cam surface 30 fully.

In FIG. 8 there is shown a surface mount flush type hinge 100 comprisinga flange 11 (the flange of hinge 10), and a strap 13a like the strap 13of hinge 10, except that the strap is of the flush type and having anarm 40a similar to arm 40 except that it is in the plane of back wall17. The back wall is attached to a door jamb in the plane of a door towhich arm 40a is attached. I

In FIG. 9, there is shown a hinge 10b like hinge 10 except that thestrap has an arm 40b of less length than arm 40. This hinge is also asurface mount offset type hinge.

In FIG. 10 there is shown a hinge 10c which is like hinge 10a exceptthat the arm 40c of its strap is shorter than ann 40a of hinge 10a. Thishinge is also a surface mount flush type hinge. i

In FIGS. 11 to 16 there is shown an edgemount type hinge 10d comprisingflange and a strap 61 cooperating therewith Flange 60 is attached to anedge of a door jamb 62 while the strap 61 is attached to an edge of adoor 63. Flange 60 comprises a casting 66 having a back wall 67 from thelower end of which a socket portion 68 extends forwardly. The casting 66is narrower than member 11 so as to fit an edge of the door jamb. Itssocket portion 68 is constructed like socket portion 18 of said member11, although narrower in dimension. The socket portion 68 has anupwardly opening socket 69 similar to socket 19. A cammember 70 similarto cam member 23 fits into the socket 69 and has a socket 70a similar tosocket 29 of cam 23.

Flange 61 is also narrow to fit an edge of a door. It has side wall 71,and upper and lower symmetrical portions 72 formed with alignedhexagonal through openings 73 and a hollow chamber or cavity 74therebetween bounded at the side by said sidewalls 71 and at the rear bya back wall 75 formed with three parallel vertically aligned horizontalthrough slots 76 for screws 77. The screws have heads 77a and shanks77b. The shanks pass through the slots 76 and screw into an edge of thedoor 63. The inner side of wall 75 is formed with vertical serrations orteeth 78. Placed against the inner serrated side 78 of wall 75 is anadjusting plate 80 having round holes 81 through which shanks 77b of thescrews 77 pass. The heads 77a of the screws contact the plate. The sideof plate 80 which is against the serrated side 78 of wall 65 issimilarly vertically serrated as at 82.

Plate 80 is narrower than the inner side of wall 75. Thus the casting 66can be adjusted sideways relative to plate 80 to adjust the position ofthe strap 61 relative to the door. I

Slidably mounted in cam member 70 is a follower 90 similar to follower55. The cam member 70 is formed at the lower end of its socket 70a witha cam surface similar to cam surface 30. The follower 90 has at itslower end a complementary cam surface similar to cam surface 57 offollower 55. Said cam follower 90 has an axial hexagonal socket 91receiveing the lower end of a hexagonal rod 92 fixed thereto and whichprojects up and is slidably inserted into the hexagonal through hole 73of the lower portion 72 of casting 66. The upper and lower end ofcasting 66 have a countersunk depression 94 receiving a cap 95 at eitherend. Cap 96 has bifurcated fingers 95a projecting down into the upperhexagonal hole 73. The lower end of rod 92 is fixed in socket 91. It hasa groove at its upper end carrying an O-ring 98.

To change the hinge from a right hand door hinge to a left hand doorhinge, the cap 95 is removed, the screws 77 are removed; member 66 ispulled up off rod 92 and rotated 180 in its plane to bring its upper enddown and its lower end up. The now lower end is then fitted on rod 92and the screws reapplied.

The open side of socket 74 may be closed by a plate or plug 100. Saidplate 100 may have fingers 101 to frictionally engage the inner surfacesof side wall 71 to hold the plate in place. When the plate 100 isremoved a screw driver can be inserted, to turn the screws 77.

It will thus be seen that there is provided an article in which theseveral objects of this invention are achieved, and which is welladapted to meet the conditions of practical use.

As possible embodiments might be made of the above invention, and asvarious changes might be made in the embodiments above set forth, it isto be understood that all matter herein set forth or shown in theaccompanying drawings, is to be interpreted as illustrative and not in alimiting sense.

1 claim:

1. A hinge comprising one part formed with an upwardly facing camsurface and a second part having a portion formed with a throughopening, and a third part comprising a follower rotatably and slidablymounted on said one part and having a downwardly facing cam surfacecomplementary to the cam surface of said first part and a rod fixed tosaid follower and projecting thereabove and slidably and non-rotatablyengageable in said through opening from either end of said opening, saidthird part having means to move said second part axially upwardly uponrotating said second and third parts together from a predeterminedangular position of said second and third parts relative to said firstpart.

2. The combination of claim 1, said hinge constituting a door hinge,said one part having means for attachment to a door jamb, said anotherpart having means for attachment to a door.

3. The combination of claim 1, said cam surfaces being symmetrical abouta plane passing through the axis of said' follower.

4. The combination of claim 1, said one part constituting a hingeflange, said second part constituting a hinge strap.

5. The combination of claim 1, said one part comprising a socket partand cam member fixed therein and formed with said bore, said cam memberand said follower being made of rigid plastic material.

6. The combination of claim 1, said one part comprising a flange havinga back wall formed with a back surface to contact a surface of a doorjamb, means to attach said flange to said door jamb, said second partcomprising a strap provided with a strap arm having a surface tocontacta door, means to attach said said strap arm to said door, said surfaceof said arm being inclined to said back surface of said flange andtoward said back surface in a direction away from the axis of said boreand follower, when said cam surfaces are fully in contact and said dooris in closed position.

7. The combination of claim 6, said cam surfaces being symmetrical abouta plane passing through the axis of said one part and follower andperpendicular to said back surface of said back wall.

8. The combination of claim 1, and cap means to close the end of saidthrough opening opposite the end thereof into which said rod isinserted, and said second part having means on opposite ends of saidthrough opening to receive said cap.

9. The combination of claim 1, said one part having a back wall, andmeans extending from the lower end of said back wall and formed with abore to receive said follower said portion of said second part beinglocated above said extending means of said one part.

10. The combination of claim 1, said second part having a wall formedwith transverse slots and with serrations parallel to the axis of saidfollower, a plate having serrations on one side complementary to theserrations of said wall, said plate being formed with screw holesregistering with said slots for screws to be screwed into a door,whereby a mount said second part on said door in various adjustedpositions relative to said door.

11. The combination of claim 10, said second part 14. The combination ofclaim 1, said second part comprising a surface mount offset door strap.

15. The combination of claim 1, said second part comprising a surfacemount flush door strap.

16. The combination of claim 1, said through opening and rod beingpolygonal in cross-section.

17. The combination of claim 1, said cam surfaces having dwells in thefully open and fully closed positions of said hinge.

18. The combination of claim 1, said one part, follower and rod beingcoaxial.

19. A door hinge comprising a flange part having a back wall and aforward extension formed with an upwardly opening socket, a cam memberfixed in said socket, said cam member having an upwardly opening socketformed with a cam surface at the lower end of its socket, a followerrotatably and slidably mounted in said socket of said cam member, andformed with a cam surface at its lower end complementary to the firstmentioned cam surface, a non-circular rod fixed to said follower andprojecting above said follower, and a strap part having a non-circularthrough hole, said rod being slidably and non rotatably receivable insaid through hole from either end thereof, said follower and rod beingmovable together axially, upon rotation of said strap part from apredetermined angular position and means to move said strap part as saidfollower are rod more axially.

20. The combination of claim 19, said surface of the other of saidelements being inclined to said surface of said one element when saidcams are in full contact.

21. A door hinge comprising a flange part having a back wall and aforward extension formed with an upwardly opening socket a cam memberfixed in said socket, said cam member having an upwardly opening socketformed with a cam surface at the lower end of its socket, a followerrotatably and slidably mounted in said socket of said cam member, andformed with a cam surface at its lower end complementary to the firstmentioned cam surface, said follower having a noncircular rod fixed tosaid follower and projecting above said follower, and a strap parthaving a non-circular through hole, said rod being slidably and nonrotatably receivable in said through hole from either end thereof.

22. A hinge comprising a pair of hinge parts, means to attach one partto a surface of a door jamb, means to attach the other part to a surfaceofa door, one part having a socket formed with and cam means coaxialwith said socket, a follower rotatably and slidably received in saidsocket coaxially thereof, and having end cam means complementary to thecam means of said socket, an axial non-circular rod extending up fromsaid follower, said other part having means at both ends to slidably andnon-rotatably receive said rod, said cam means of said socket andfollower, being symmetrical about a plane passing through the axis ofsaid socket and follower and perpendicular to one of said surfaces,whereby said other part can be slid off the rod, in a first position ofsaid other part and reversed 180 in its own plane and then slidablyremounted on said rod in a second position thereof, and said other partwill rise on one part of the socket cam means when said other part isturned 180 in one direction from said first position and will rise onanother part of said socket cam means when turned 180 in an oppositedirection from said second position; whereby said other part may be usedwith a left hand door or with a right hand door.

23. The combination of claim 22, said cam means of said socket and cammeans of said follower, having full contact in the dropped position ofsaid other part, and dwell means to hold said other part on raisedposition when said other part is turned l from either the first orsecondpositions, and said other part will drop by gravity to self-close thedoor to which it is attached when said other part is moved past saiddwell, in directions back toward either first or second position.

1. A hinge comprising one part formed with an upwardly facing camsurface and a second part having a portion formed with a throughopening, and a third part comprising a follower rotatably and slidablymounted on said one part and having a downwardly facing cam surfacecomplementary to the cam surface of said first part and a rod fixed tosaid follower and projecting thereabove and slidably and non-rotatablyengageable in said through opening from either end of said opening, saidthird part having means to move said second part axially upwardly uponrotating said second and third parts together from a predeterminedangular position of said second and third parts relative to said firstpart.
 2. The combination of claim 1, said hinge constituting a doorhinge, said one part having means for attachment to a door jamb, saidanother part having means for attachment to a door.
 3. The combinationof claim 1, said cam surfaces being symmetrical about a plane passingthrough the axis of said follower.
 4. The combination of claim 1, saidone part constituting a hinge flange, said second part constituting ahinge strap.
 5. The combination of claim 1, said one part comprising asocket part and cam member fixed therein and formed with said bore, saidcam member and said follower being made of rigid plastic material. 6.The combination of claim 1, said one part comprising a flange having aback wall formed with a back surface to contact a surface of a doorjamb, means to attach said flange to said door jamb, said second partcomprising a strap provided with a strap arm having a surface to contacta door, means to attach said said strap arm to said door, said surfaceof said arm being inclined to said back surface of said flange andtoward said back surface in a direction away from the axis of said boreand follower, when said cam surfaces are fully in contact and said dooris in closed position.
 7. The combination of claim 6, said cam surfacesbeing symmetrical about a plane passing through the axis of said onepart and follower and perpendicular to said back surface of said backwall.
 8. The combination of claim 1, and cap means to close the end ofsaid through opening opposite the end thereof into which said rod isinserted, and said second part having means on opposite ends of saidthrough opening to receive said cap.
 9. The combination of claim 1, saidone part having a back wall, and means extending from the lower end ofsaid back wall and formed with a bore to receive said follower saidportion of said second part being located above said extending means ofsaid one part.
 10. The combination of claim 1, said second part having awall formed with transverse slots and with serrations parallel to theaxis of said follower, a plate having serrations on one sidecomplementary to the serrations of said wall, said plate being formedwith screw holes registering with said slots for screws to be screwedinto a door, whereby a mount said second part on said door in variousadjusted positions relative to said door.
 11. The combination of claim10, said second part having a chamber disposed between the ends of saidthrough opening, and means to removably close said chamber.
 12. Thecombination of claim 1, said rod being provided with O-ring meansengaging the inner surface of said through opening.
 13. The combinationof claim 1, said parts comprising parts of an edgemount hinge.
 14. Thecombination of claim 1, said second part comprising a surface mountoffset door strap.
 15. The combination of claim 1, said second partcomprising a surface mount flush door strap.
 16. The combination ofclaim 1, said through opening and rod being polygonal in cross-section.17. The combination of claim 1, said cam surfaces having dwells in thefully open and fully closed positions of said hinge.
 18. The combinationof claim 1, said one part, follower and rod being coaxial.
 19. A doorhinge comprising a flange part having a back wall and a forwardextension formed with an upwardly opening socket, a cam member fixed insaid socket, said cam member having an upwardly opening socket formedwith a cam surface at the lower end of its socket, a follower rotatablyand slidably mounted in said socket of said cam member, and formed witha cam surface at its lower end complementary to the first mentioned camsurface, a non-circular rod fixed to said follower and projecting abovesaid follower, and a strap part having a non-circular through hole, saidrod being slidably and non rotatably receivable in said through holefrom either end thereof, said follower and rod being movable togetheraxially, upon rotation of said strap part from a predetermined angularposition and means to move said strap part as said follower are rod moreaxially.
 20. The combination of claim 19, said surface of the other ofsaid elements being inclined to said surface of said one element whensaid cams are in full contact.
 21. A door hinge comprising a flange parthaving a back wall and a forward extension formed with an upwardlyopening socket a cam member fixed in said socket, said cam member havingan upwardly opening socket formed with a cam surface at the lower end ofits socket, a follower rotatably and slidably mounted in said socket ofsaid cam member, and formed with a cam surface at its lower endcomplementary to the first mentioned cam surface, said follower having anon-circular rod fixed to said follower and projecting above saidfollower, and a strap part having a non-circular through hole, said rodbeing slidably and non rotatably receivable in said through hole fromeither end thereof.
 22. A hinge comprising a pair of hinge parts, meansto attach one part to a surface of a door jamb, means to attach theother part to a surface of a door, one part having a socket formed withend cam means coaxial with said socket, a follower rotatably andslidably received in said socket coaxially thereof, and having end cammeans complementary to the cam meaNs of said socket, an axialnon-circular rod extending up from said follower, said other part havingmeans at both ends to slidably and non-rotatably receive said rod, saidcam means of said socket and follower, being symmetrical about a planepassing through the axis of said socket and follower and perpendicularto one of said surfaces, whereby said other part can be slid off therod, in a first position of said other part and reversed 180* in its ownplane and then slidably remounted on said rod in a second positionthereof, and said other part will rise on one part of the socket cammeans when said other part is turned 180* in one direction from saidfirst position and will rise on another part of said socket cam meanswhen turned 180* in an opposite direction from said second position;whereby said other part may be used with a left hand door or with aright hand door.
 23. The combination of claim 22, said cam means of saidsocket and cam means of said follower, having full contact in thedropped position of said other part, and dwell means to hold said otherpart on raised position when said other part is turned 180* from eitherthe first or second positions, and said other part will drop by gravityto self-close the door to which it is attached when said other part ismoved past said dwell, in directions back toward either first or secondposition.